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Development Of New Techniques For Functional Magnetic Resonance Imaging Of The Brain

Not Applicable
Terminated
Conditions
Diagnosis, Psychiatric
Interventions
Other: fMRI
Registration Number
NCT00593931
Lead Sponsor
University of California, Davis
Brief Summary

This Protocol is intended to facilitate development and testing of new techniques for functional MRI by UC Davis Research Faculty, as well as to facilitate the evaluation of new techniques provided by the system manufacturers (GE and Siemens).

Detailed Description

New techniques covering a wide range of clinical and scientific applications will be developed, tested and evaluated. These include 1. Investigation of sensory stimulus processing and cognitive processing, both in normal subjects and patients with psychiatric disorders, 2. Early detection of stroke and other ischemic injury, and 3. Characterization of tumor distribution and activity. The new techniques will routinely need to be tested with respect to the following: 1. Sensitivity to blood oxygenation versus blood flow versus blood volume contrast mechanisms, 2. Signal-to-noise and contrast-to-noise ratio, 3. Spatial and temporal resolution, 4. Distribution and severity of image artifacts, and 5. Duty cycle limitations. Most clinical applications will require coverage of the entire brain and consequently high duty cycle operation, which needs to be traded off with spatial and temporal resolution, as well as contrast mechanisms. The work will also involve the testing of different experimental paradigms (time sequence of stimuli or cognitive tasks) to identify that which provides the highest signal change associated with the specific brain activity of interest.

Although 3T provides twice the signal of 1.5T systems, for some research applications this image quality advantage of 3T may be outweighed by other effects of higher field on the signal. Consequently, most new techniques will be evaluated on both the 1.5T and 3T systems, and a decision will be made based upon the overall image quality, regarding which system is to be used.

The Protocol does not involve injection of any contrast agent or drug, or other minimally-invasive or invasive procedure. It is intended specifically for those studies in which the subject is required, in addition to trying to relax and lie still, only to experience and respond to various non-harmful sensory stimuli, or to perform common cognitive (e.g. math calculations) and or motor (e.g. finger tapping) tasks.

Recruitment & Eligibility

Status
TERMINATED
Sex
All
Target Recruitment
215
Inclusion Criteria
  • 18 years of age or older
  • ability to give informed, written consent
  • Not pregnant or breastfeeding
Exclusion Criteria
  • Electrically, magnetically, or mechanically activated implants (for example, cardiac-pacemakers)
  • Ferromagnetic implant, such as an aneurysm clip, surgical clip, or prosthesis
  • History of uncontrolled claustrophobia

Study & Design

Study Type
INTERVENTIONAL
Study Design
SINGLE_GROUP
Arm && Interventions
GroupInterventionDescription
AfMRINormal Subjects
Primary Outcome Measures
NameTimeMethod
transient changes in blood flow in the brain that occurs with neuronal activityPost-scanning
Secondary Outcome Measures
NameTimeMethod
Sensitivity to blood oxygenation versus blood flow versus blood volume contrast mechanismsPost-scanning
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